When Google unveiled Buzz earlier this week, one of the first things that jumped into many people's minds (including ours) was "haven't we seen this before?" The answer is yes.

Buzz is, in many ways, highly derivative of existing, and quite popular services. The three biggest ones that come to mind are Twitter, Facebook, and FriendFeed, with the latter two being the same company. Though to Google's credit, it has done something none of these companies has managed to do in integrating it deeply into a popular e-mail service.

While there are too many differences to make an apples to apples comparison here, there are a lot of key features the four services share. Read on to find out which of these features each service is the best at.

The compose box

Click to see full-sized.Photo by Screenshot by Josh Lowensohn/CNET

All four of these services let users send out a status update that consists of text. With the exception of Twitter, all can also let you attach multimedia objects like photos and videos. Twitter is also the only one of the four to have a character limit, although users can go beyond it if they want. The result is that the tweet will get truncated, and will only be able to be viewed in its full form on Twitter.com.

Buzz, FriendFeed, and Facebook all allow users to designate who they want to send a message to, be it one or a group of specific users. Twitter users, on the other hand, are able to send a private message (called "direct" messages) to just one user at a time.

Out of the four, FriendFeed and Facebook tie in terms of being the most liberal in what people can share in their posts. For instance, FriendFeed has its own file storage service, where users can upload files of any size from their computer. Similarly, Facebook's compose box has tools for not just photos and links (which Google Buzz users have), but also videos and events. Facebook also does a much better job than Google Buzz in terms of letting users see what a shared link will look like prior to posting, as well as letting them edit whatever information it's grabbed from the site being linked.

Winner: This is a subjective battle, and one that's not completely fair considering all four have alternate post boxes when you're using them from a mobile device. Also, Buzz is the only one of these four that does not yet allow outside developers to post to a user's feed. So, with that said--in the framing of this battle, Twitter's box wins out in terms of simplicity. And Facebook and FriendFeed both do a killer job at letting users add the most types of media to their posts, while Buzz's box is limited to links and photo uploads. At least for now.

Privacy settings

Privacy is one of the most important features among these four services, and one that's become increasingly of interest as these social networks grow to encompass a user's private and public life.

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In terms of the highest granularity of privacy controls between these services, Facebook and FriendFeed offer the most ways at controlling who can see your information both on a post-by-post basis and with your overall feed. This is followed closely by Buzz, then Twitter--both of which have a similar "all or nothing" approach when it comes to sharing your feed to everyone, or just people you've approved. Buzz edges out Twitter slightly, by letting you send out updates to specific groups of people, which Facebook and FriendFeed are also capable of doing.

Buzz initially brought several privacy concerns to the table--the main one being that users were opening up their Gmail in-box (and Google profile) to a large group of people that could fill it with incoming information. And when used from a mobile phone, Buzz can keep track of a user's location and share it with an outgoing post. Although this is nothing groundbreaking, as Twitter has had a geo-API since August.

Where Buzz really got into trouble (when it first launched) was by doing a few things automatically, even before users were given a chance to make changes. The first was to automatically follow everyone who was on a user's contact list, then making that information public to other registered Google users on that user's Google profile. It didn't share their e-mail addresses or phone numbers, but it did give people a very clear idea of who a user was sending e-mails to.

Buzz also began automatically posting shared items from Google Reader, as well as people's Picasa Web public albums and Google Chat status messages. We'll give Google a pass on the publicly available Google Reader and Picasa items, but sharing one's chat status without asking should be a no-no. At least it's a quick settings menu away from being able to be turned off.

Though Google deserves some credit for reacting quickly, and listening to what users wanted in the way of privacy. Google launched Buzz on Tuesday, and it rolled out its first major privacy update two days later. This update put several privacy options up front for people were using the service for the first time. This included a toggle to make your following and follower list private or public, as well as a way to block people outside of their Buzz page or Google profile. Google also separated people's lists of followers into those that had one of Google's public profiles, and those that didn't.

Winner: All four services let you completely secure your updates to a list of people you choose, which is about as secure as it gets when blasting information out onto the Web. Facebook, FriendFeed, and Buzz have the best privacy settings when it comes to quickly choosing who you want to see a message, while Facebook takes the cake in terms of letting users choose who can see what types of information on their profile at large. Our main qualm with Buzz is that the privacy settings remain fragmented between Buzz's own settings (that are not within the Gmail settings menu), and Google profile settings. Google really should unify these in one menu, along with adding a way to break down who can see what types of content you're posting.

Follower management

Followers are a key part of all of these services, since that's who you're letting see whatever is being posted. In terms of the various follower menus, the four services chop them up like this:

Click to see full-sized.Photo by Screenshot by Josh Lowensohn/CNET

Facebook's follower management tools are actually split up into two different menus--the friends list and the privacy settings menu. Users do most of the adjustments on who can see what in the service's privacy settings panel. And to completely block out anyone from getting updates, a user doesn't need to de-friend them. Instead, they can simply add them to Facebook's block list. FriendFeed, Twitter, and Buzz also have this feature.

Buzz's approach to helping users manage who they're following, and who's following them, is the same one Google has used within Gmail. This takes the form of a pop-up window of your contacts, which doubles as a search tool to find people who have public Google profiles. This isn't as advanced as what FriendFeed and Twitter offer, with a followers list that can be sorted, and viewed 80 and 20 followers at a time (respectively). Though one thing Buzz does well is show users who has just started following them between breaks in using the service, so that they can very quickly follow them back the next time they sign on. It also combines the follower and following menu into one list, which is a nice touch.

To FriendFeed and Twitter's credit, both have APIs that let third parties access a user's followers and following list, and make adjustments to it. There have been a handful of tools to come out of this, that let users more easily follow back people who have followed them, as well as weed out large groups of followers at once. See Twitter-to-FriendFeed and Twitter Karma as two good examples of what can be done with this functionality.

Winner: There's no real winner here. Each service has its own strengths and weaknesses. And as mentioned in our debate about Buzz from earlier this week, no service with follower functionality has really given users a simple, yet powerful way to deal with a large number of followers in a way that makes it easy to discover whether it's worth following them back. Though considering Buzz has its own recommendation engine for content, we could see something similar bubble up for recommending users with similar tastes.

Search

Once a neglected feature, search has become an integral part of using these sites. All have real-time search engines, which let you find posts from your friends, or each community at large, as soon as they've been posted.

The same search term, run on all four search engines. Click to see the full-sized image.Photo by Screenshot by Josh Lowensohn/CNET

Despite being from Google--the current king of search engines--the search tool that's been built into Buzz is arguably the worst at letting you whip through its results. The main reason for this is that it organizes content by relevancy instead of how recent it is. For search results from the Web this works in Google's favor, but in the case of Buzz posts, you're more likely to be looking for recent mentions of something, than what its algorithms think are the best match. Google has also failed to put some of the advanced features within easy reach of users, by requiring them to remember search operators, instead of offering settings toggles like it does on the Google search home page.

If you know Buzz's keyboard shortcuts, and search operators, Buzz's search engine can be tamed. Though again, it does the poorest job of the bunch in terms of displaying the results in a user-friendly manner.

One of our favorite features, which can be found in Twitter and FriendFeed's search, is the option to save a search query for later use. In both cases, these saved searches hang out on the right side of each social network's interface where they can be run again whenever the user feels like it. FriendFeed also takes that a step further by letting users pop out a search they just ran, as its own window which updates in real time. That same search can also be embedded on third-party sites, which is a neat trick.

Speaking of real-time updating, Buzz is the only search tool among the four that does not alert users to new updates in its results. Twitter provides a subtle notification at the top of the search that new results are ready, while FriendFeed and Facebook can both stream in the latest results as soon as they come in. The edge between those two goes to FriendFeed, which users can actually pause.

Winner: Out of the four, we found Twitter and FriendFeed's search tools to be the easiest to use, yet with the most advanced features. Both can be used without ever having to sign up with an account, and both allow users to save searches for later use.

Is Google likely to improve on Buzz's search? Without question. But for now, these other services offer a better search experience.

Content discovery and filtering the noise

One of the things Google said when it announced Buzz, is that it's been designed from the ground up to make it easier to find content you'll care about.

To that end, Buzz has a built-in recommendation engine that brings in new posts from people you're not following. These are picked out by taking items your friends have liked from other people's buzz streams. Buzz lets users agree or disagree with the recommendation. And each time this happens, Google learns the user's tastes to affect future recommendations.

The Google Buzz recommendation engine suggests new items you might be interested in, even if they're not from people you follow.Photo by Josh Lowensohn / CNET

Along with its recommendation engine, Buzz also has a quick way to get rid of conversations you don't want to see. Just like you can in Gmail, Buzz lets you "mute" any item, which hides the conversation from your view, along with keeping future comments from showing up in your Buzz in-box counter. At the same time, muting a conversation doesn't keep @ replies from showing up in your in-box, meaning you won't miss future conversation directed at you.

So how does this stack up against the other networks? Facebook and FriendFeed give users the option to hide incoming content. FriendFeed also offers users a way to "hide other items like this one" which can hide all the items from that particular person, or just entries from a specific source--like if it's a status update slurped up from Twitter, or a blog post from that person's personal blog.

Twitter on the other hand, offers no hiding feature. Instead, users can make lists of certain people, and just limit the stream to content from those folks. Facebook and FriendFeed let users do this too.

As for content discovery, Facebook splits its news feed into a chronological view of the latest content, while having a "top news" section that is what Facebook considers to be the "most interesting." This is based on your relationship with the person who is posting the content, what type of content it is, and how many comments it has from other users.

Twitter filters up the top content in terms of trends. These show up on a user's side bar, with links to the latest tweets that have that keyword.

FriendFeed does something interesting, that Buzz actually implemented, by showing content from people you may not be following. These items are called "friend-of-a-friend" entries. There's also a "best of the day" section, which is a feed of the most popular entries from the past day, week, or month from people you're friends with.

Winner: FriendFeed came out as the clear winner in these two combined categories. It does a good job at helping surface new or otherwise interesting content, and explaining why you're seeing it, while providing powerful tools to help curb the noise from becoming overwhelming. Buzz's tools are certainly off to a good start with things like the recommendation engine and muting, but it doesn't offer nearly as much control when it comes to turning off certain kinds of entries from specific people.

Conclusions

Buzz is a young service, and unlike some of the services it's being compared to, it's not nearly as feature complete. But based on Google's quick reaction to user privacy needs this past week, along with the company's quick development in its Gmail product, it's not unreasonable to imagine Buzz becoming a much more user-friendly and powerful service in just a few months time. This is especially true given that Google will be launching an enterprise version of the product later this year.

Where Buzz is really getting beat out by some of these other services is its search tool, which is uncharacteristically difficult to use by comparison, along with its controls for both adding and controlling content feeds and controlling who gets to see what. Making these easier to use, as well as really refining the privacy menu into a single location, would go a long way toward making Buzz a more complete social service.